[Critical ischemia of the leg. A technique for distal anastomosis in a a small caliber artery].

Unlabelled: CRITICAL ISCHEMIA OF THE LOWER LIMBS: This type of lesion, which spontaneously progresses to gangrene and amputation, is encountered more and more frequently. Emergency endoluminal revascularization or bypass surgery is required. When conventional endoluminal techniques cannot be used, a distal graft using the autologous saphenous vein is a promising alternative to achieve patent vascularization and salvage the limb.

If Venous Material Is Not Available: Usable venous material is not always available due to varicosities, thrombus formation, small size or previous surgery (stripping, coronary surgery, prior revascularization procedure); rates reported range from 20 to 40%. For such patients, other veins (external saphenous, arm veins, superficial femoral veins) may be useful but are not always appropriate for distal repair. Different prostheses might also be used but again do not always provide improved permeability. Most teams however use a polytetrafluoroethylene stent for revascularization of the distal leg. Different technical improvements favor success of prosthetic bypasses, but when used below the knee, flow remains less satisfactory than with venous bypasses.

Vein Cuffs: This procedure is a common adjuvant technique positioning a venous cuff between the recipient artery and the prosthesis. The cuff avoids the direct contact between the prosthesis and the fragile artery that is often difficult to suture.

Results: Several series have demonstrated that the rate of success of vein cuff procedures remains lower than venous bypass procedures, but also that flow is better than with simple femorotibial prostheses.

Pathogenic Hypotheses: The reduction of the neo-intimal hyperplasia observed in experimental models is insufficient to explain entirely the observed in vivo benefit. The fact that the suture is easier to make is one possible reason. Indeed the rate of failure of simple prosthetic bypass surgery is high in the immediate postoperative period. These cases of thrombosis result from technical insufficiencies and are undoubtedly overcome by the use of the venous cuff.